Valves for the control of fluids



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VALVES FOR THE CONTROL OF FLUIDS Filed July 15, 1960 6 Sheets-Sheet 6 United States Patent 3,139,801 VALVES FOR THE CONTROL OF FLUIDS Stauiey G. Shand and Herbert Bentley-Leek, Hereford,

England, assignors to Saunders Valve Company Limited, Cwmbran, Monmouthshire, England, a British company Filed July 15, 1960, Ser. No. 43,084 Claims priority, application Great Britain July 16, 1%59 17 Claims. (Ci. 91-189) It is often required to provide an assembly of valves to control the operation of hydraulic devices automatically in a certain sequence of operations and the present invention provides such an assembly.

The assembly is intended to control the operation of equipment used in mining hereinafter referred to as equipment of the kind described and diagrammatically illustrated in FIGURES 5, 6 and 7 of the accompanying drawings which comprises a series of chocks, one shown at C, incorporating hydraulic jacks, two shown at J, J carrying bearers B, supporting the roof R of the mine gallery while the face F is being excavated by a machine M hauled along the gallery and delivering into a conveyor C0 extending along the gallery between the chocks and the path of the machine. Following the passage of the machine past each chock, the jacks are slightly released and a horizontal hydraulic ram HR pulls the chock towards the conveyor whereafter the jacks are again pressed towards the roof. The bearers B extend towards the face well beyond the front jack I so that the roof is supported over the conveyor and over the path of the machine in sections and the supports are advanced chock by chock so that the unsupported section of the roof is kept at a minimum. The number of jacks in a chock depends on the width of the gallery but is usually 4 or more. The jacks are mounted on a chock base CB in which the horizontal ram is carried and the forward end of the horizontal ram is anchored to the framing of the conveyor. When the machine has completed its traverse, certain of the horizontal rams which are double acting can be actuated to shift the conveyor over towards the face. In FIG- URES 5, 6 and 7 the ram HR is shown as of this double acting type.

The assembly provided by the invention for automatically controlling such equipment comprises three plug cocks, a non-return valve, a trip valve, means for mechanically actuating one of the plug cocks as the horizontal ram of the chock is drawn out by the shifting over of the conveyor, and a pressure fluid operated device controlled by the aforesaid plug cock for rotating the other two plug cocks.

The plug cocks preferred have a spherical plug which co-operates with seatings of narrow width formed on spring urged piston like members which are slidable in bores in the valve casing and sealed to these bores by O-rings or the like; these seatings define the ports with which the plug co-acts. The plug itself is provided with stout journals rotating in bushes in the valve casing and one journal is extended to constitute an operating spindle.

The trip valve need be no more than a simple cone or preferably a ball member carried at the end of a sliding stem. The control of this valve is effected by the provision of a pressure chamber in which an abutment on which the pressure from the valve controlling the support jacks reacts against an adjustable control spring. This is set so that when the pressure reaches a predetermined value the abutment yields. The pressure, also acting on a spool or piston on the trip valve stem, moves the latter and opens the trip valve. The stem may be sealed to its bore by O-rings and as the pressure may reach a very high value (say 10,000 lbs. per square inch) a discharge passage may be provided between two O-rings for any liquid which leaks along the stem. This arrangement prevents high pressure liquid from entering the low pressure system in the event of a seal failure.

The means for actuating the one plug cock from the horizontal ram may comprise a sliding rack meshing with a pinion on the spindle of the cock plug. The rack has a stem projecting from the casing and an abutment on the horizontal ram of the chock engages the stem at the appropriate point in the movement of the ram. In the opposite direction the rack is returned by a spring, an adjustable stop being provided to limit the movement of the rack in this direction.

The means for rotating the other two plug cocks preferabiy includes a slider actuated hydraulically and linked to the cock spindles in such a way that the mechanical advantage increases as the cocks close. This eifect may be obtained by providing the spindles of these cocks with crank arms and actuating them through links pivoted at one end of the crank arm and at the other to the slider, the crank arm being parallel to the slider and the links at right angles to them when the cocks are closed. The slider may be moved in the closing direction by the fluid pressure acting in a cylinder on a plunger which pushes the slider while the movement in the opposite direction is efiected by spring action. The increase in the mechanical advantage during closing maintains the loading as the force of the return springs decreases.

Alternatively to a return spring there may be a second hydraulic cylinder of different effective area acting in opposite directions. Thus when both cylinders are pressurized to the same value the slider is moved in the direction in which the larger area cylinder acts, while when pressure is removed from this cylinder the smaller area cylinder returns the slider to its original position. The smaller area cylinder may be constituted by an annulus between a hollow extension on the slider and an outer bore in which works a packed flange on the extension which itself is a sliding fit in an inner bore to which it is sealed by a packing ring. A plunger works directly in the larger area cylinder which extends into the hollow extension, the plunger abutting the bottom of the extension and so pressing on the slider.

In order that the invention may be clearly understood some embodiments thereof will now be specifically described by way of example only with reference to the accompanying diagrammatic drawings in which FIG. 1 is a section through a valve assembly according to the invention,

FIG. 2 is a section taken on the line II of FIG. 1,

FIG. 3 is a section taken on the line IIIIII in FIG. 1,

FIG. 4 is a section on the line 1V-IV in FIG. 1,

FIG. 5 is a diagram illustrating the combination of the valve assembly with mining equipment controlled by its aid, the valve assembly being in the normal position, and

FIGS. 6 and 7 illustrate the positions taken by certain of the parts at later stages in the cycle of operations.

In the valve assembly shown in the drawings there are four plug cocks 1, 2, 3 and 4. So far as functions are concerned, cock 1 is the first cock, and cock 4 is a third cock. The cocks 2 and 3 are in parallel and either can be regarded as a second cock though as will be explained later there may be more than two, or only one provided the latter has the same connections as the cock 3. For this reason in FIGURES 5, 6 and 7 only the one second cock 3 is shown, to avoid unnecessarily complicating the figures. Each of these cocks has a spherical plug SP which co-operates with seatings S of narrow width formed on piston like members P which are urged by springs H and are slidable in bores in the valve casing the piston like members P being sealed to the bores by O-rings G or the like. It will be seen that in each case the piston-like member P is of substantially the same diameter as the narrow seating S. As a result of this although the fluid pressure has access to the outer end of the piston-like member P the fluid pressure acting to urge the piston-like member axially is substantially balanced. Consideration will show that the exact action of the fluid pressure will be determined by the Width of the seating S and the outer diameter of the seating S in relation to the diameter of the piston-like member P. In view of the substantial balancing of the fluid pressure the pressure of the seating S against the plug SP will be determined mainly by the spring F. As the seating S is narrow the freedom of the piston-like member to slide in its bore is suflicient to ensure a good fit of the seating against the plug if the parts are made to reasonable tolerances and the intensity of pressure on the seating surface will be high without undue pressure by the spring, thus enabling the plug to be rotated with a comparatively low torque. In this way although as will be seen later the fluid pressure may reach very high values indeed it is still possible to rotate the various plugs with a relatively low torque yet a good tight joint will be made between the plug and the seatings which co-operate with it. These seatings generally define the ports with which the plug coacts but the annular space between the seatings may be used as an additional port and in the present assembly connects with a return line for hydraulic fluid exhausted from parts of the assembly. The return line is connected at RL (FIGURES 1 and 3) and is also indicated in FIGURE 5. The annular space around the plug I is marked 22 in FIGURE 3 and this connects to the connection RL by a passage not visible in any of FIGURES 1 to 4. In the case of the plugs 2, 3 the annular space is marked 57, and the connecting passage 57a while in the case of the plug '4 the annular space is marked 57b and the connection RL opens out of it.

The first cock plug 1 is mechanically operated, a pinion 5 carried upon the spindle 6 of the valve meshing with a rack 7. The rack 7 is operatively connected to a stem 8 which extends through the casing and the end 14 of which projects through an aperture containing a sealing ring 9. The stem 8 carries a flange 11 and a spring 12 is disposed between this flange and a seating 13 formed 'in the casing. The rack is therefore biased by the spring 12 to move to the right in FIGURE 4.

In the normal position of the valve 1 shown in FIG- URES 3, 4 and 5, which is the position occupied when the roof bearers B are forward as in FIGURE 5, the end 14 of the member 8 is in contact with an abutment A on a double acting horizontal ram HR and the spring 12 is fully compressed. With the valve in this position a duct 15 in the first plug 1 connects an inlet 16 for hydraulic fluid coming under pressure from the outlet 33 of the preceding valve assembly or from a separate supply in the case of the first assembly of the series, to a port 17 which is in turn connected through passages 17a, 17b to a primary trip valve 18. The other duct 19 in the plug 1 connects a port 21 to the annular space 22 leading by a passage not shown to the hydraulic return line RL. As will become apparent later, this cuts off hydraulic pressure from actuating means for valves 2, 3 and 4 and these are also in the normal position shown in FIGURES 1, 3 and 5.

With the valves in this position, valves 2 and 3 acting in parallel, through diametral ducts 25 in their plugs connect a common hydraulic supply from an inlet 23 to outlets 24 leading by pipes such as 24a (FIGURE 5) to respective roof supporting jacks J. This supply reaches the valves 2 and 3 through non-return valves 26, so that even if the hydraulic supply should fail or the back pressure from the jacks exceed the supply pressure due to settlement of the supported strata, the jacks will not lower.

The fluid in the outlets 24 can also pass through a passage 28 (FIGURES 3 and 5) into a space 27 (FIGURES 4 and 5) to bear against the underside of the head of a at all therchocks.

plunger 35 and lift it against springs 31, the initial compression of which is adjustable by means of a screw 32. Movement of the plunger 35 to the right as seen in FIG- URES 4 and 5 against the bias of the springs 31 allows the trip valve 18 to open so that a direct passage is provided between the inlet 16, duct 15, outlet 17, passages 17a, 17b and the outlet 33 (FIGURES 4 and 5), whence a pipe 33a FIGURE 5 leads to the inlet 16 of the next assembly in the series. In any one assembly therefore, when the trip valve 18 opens, pressure fluid flows in at the inlet 16 and thence through the outlet 33 leading to the next assembly. To avoid leakage of hydraulic fluid from the space 27 (in which the back pressure from the jacks may reach a very high value) reaching the outlet 33, seals 34 (FIGURE 4) are provided where the plunger 35 passes through the bore in the casing and a drain 36 is provided between the seals.

The pressure of the fluid in the outlets 24 also moves a plunger 37, FIGURES 3 and 5, and lifts a secondary trip valve formed by a ball 38 against the bias of a spring 39 to allow fluid to pass from a supply connected at 44 through the duct 45 in the plug of the valve 4, the port 42 and space 41 to the outlet 43. The outlet 43 leads by pipe 43a (FIGURE 5) to the rear end of the cylinder of the double acting ram HR. At the appropriate time, as will be explained, this serves to advance the conveyor C0 and to bring this into an appropriate position to receive the mined material discharged by the cutting machine M at a later pass, but the conveyor is fixed in position in FIGURES 5, 6 and 7, and while it is so fixed this pressure causes no movement of the ram because the conveyor resists it.

As above mentioned the valves are in the normal position when the chock is in the position shown in FIGURE 5 in which the end 14 of the stem 8 is fully depressed by the abutment A, the bearers B are right forward after the machine M has passed and the jacks J are under pressure. To enable the fully depressed position of the stem 8 to be regulated there may be an adjustable abutment 8a. Also the abutment A is adjustable in position to enable the precise point at which the movement of the ram HR in this direction terminates to be regulated. The conveyor framework in this mode of working is fixed down before the passage of the machine. Then, when all the chocks of the series are in position, the machine M has been returned to the starting end and has cut into the face F the appropriate depth for the next pass, the first step is to shift the conveyor C0 forward towards the machine M to the appropriate position. As all the jacks J are under pressure, all the secondary trip valves 38 are open and as the valves are all in normal position there is a supply connected from 44 through the ducts 45 of each valve 4, port 42, trip valve 38, outlet 43 and pipe 43a to the back end of the cylinder of the ram HR. At the same time the front end of each cylinder is connected to the return line RL by way of pipe 61a, outlet 61, port 59 and a duct 65 in each valve 4, this duct 65 opening into the space 57b leading to the return line RL. If now the conveyor framework is released, since the pressure reaction of the jacks J holds the chock bases CB firmly in place, the ram HR under the pressure supply to the back end of the cylinder of the ram HR pushes the conveyor over to the right in FIGURE 5 through the required distance, the fluid escaping from the front end of the cylinder via 61a, 61, 59, 65, 57b and RL. If desired the hand controls described below can be used to effect this movement step by step rather than simultaneously Once the conveyor C0 is in its new position its framework is again fixed down.

It may be mentioned that a ram HR for shifting the conveyor C0 need not be provided at every chock. At those chocks not so provided only single acting rams for drawing the chock over towards the conveyor are necessary, i.e. rams to the front end only of the cylinder of which a supply is needed. Also instead of using double acting rams on the chocks which elfect the shifting of the conveyor, two oppositely acting single acting rams can be provided.

When the rams shift the conveyor over as above described, the abutments A leave the ends 14 of stems G and the latter are therefore moved by the springs 12 to their other end positions, thus changing over all the valves 1 through the racks 7 and pinions 5, FIGURE 6. The inlet 16 to each is thereby connected through the duct 15 to the port 21 while the port 17 leading to the trip valve 18 is connected through the duct 19 to the hydraulic return line RL through the annular space 22.

This results in the hydraulic supply to the outlet 33 of each assembly and thus to the inlet 16 of the succeeding assembly connected via 33a to this outlet, losing pressure, even though the trip valves 18 remain open.

The inlet 16 of the first assembly of the series has an independent pressure fluid supply but it is not advisable that this should be permanently connected to the supply. A manually operable master valve MV may therefore be provided in the supply to the inlet 16 of the first assembly to control the start of the sequence of operations which follows.

Until there is a supply to the inlet 16 of the first assembly, the changing over of the valves 1 is the only result of the movement of the rams HR to shift over the conveyor C0. The parts are then in the position shown in FIGURE 6.

When the supply is provided to the inlet 16 of the first assembly, the pressurized fluid will then pass from this inlet 16 through the duct 15 in the plug of valve 1 to the port 21 from whence an internal passage 46 (FIGURE 3) leads the fluid to exert pressure upon the shoulder 47a of the head of a plunger 47, FIGURE 2. At the same time the port 17, connected by way of passages 43, 49 (FIGURE 3) and 51 (FIGURES 2, 5 and 6) to the cylinder 52 (FIGURES 2 and 6) in which the head of the plunger 47 works is connected to the hydraulic return line RL by way of the duct 19 and the annular space 22. The plunger 47 accordingly moves to the left from the position shown in FIGURES 2 and 6 displacing fluid from the cylinder 52 and carrying with it a slide 53 (FIGURE 2) which is connected by links 54 with cranks 55 upon the spindles of valves 2, 3 and 4. These valves are thereby each turned counter-clockwise through 45 to the position shown in FIGURE 7.

When valves 2 and 3 are turned into this position, the supply from the inlet 23 is blocked off by them (see valve 3 in FIGURE 7) and the roof supporting jacks I which are connected by pipes such as 24a to the outlets 24, are released because the fluid from the jacks passes through the pipes 24a, and ducts 56 in the valve plugs 2, 3 to the annular space 57 connected by the passages 57a to the hydraulic return line RL. At the same time as the jacks J are relased by this means, the duct 45 in the valve 4 connects the hydraulic supply from inlet 23, passage 23b and port 58 to port 59 and outlet 61 leading by the pipe 61a to the front end of the cylinder of the horizontal ram, HR.

Owing to the release of pressure in the jacks, the pressure behind the plunger 47 will also have been released and the secondary trip valve ball 38 will have closed, but this is only under the light pressure of the spring 59. Accordingly, when the jacks move out of contact with the roof and thus relieve the load on the chock base CB, since the conveyor Co has been fixed down and the ram HR is therefore fixed, the pressure supply to the forward end of the cylinder of the ram HR causes the cylinder to draw the chock over towards the conveyor C0, the pipes 43a and 61a being flexible to permit this, and the fluid from the rear end of the cylinder is forced out through the pipe 43a and outlet 43, lifting the valve 38 against the light pressure of the spring 39 and thence escaping through the port 42 and a duct 62 in the valve 4 which opens into the space 591) to the hydraulic re- 6 turn line RL. FIGURE 7 illustrates the position when the chock has moved over part way.

As the chock advances towards the conveyor Co under the hydraulic drive, it is finally brought into the position of FIGURE 5 where the bearer B is over the machine M and the end 14 of the stem 8 again contacts the adjustable stop A on the ram. This pushes the stem 8 into the casing and through the rack 7 and pinion 5 restores valve 1 to its normal position shown in FIGURE 5. The hydraulic fluid supply from inlet 16 is then directed by duct 15 and passages 48, 49, 51 into the cylinder 52 to move the plunger 47 to the right in FIGURE 2. Fluid displaced by the plunger returns through passage 46, port 21 and duct 19 to the hydraulic return line RL. As the plunger 47 moves, valves 2, 3, and 4 are restored to their normal positions. The roof supporting jacks are pressurized through valves 2 and 3 and the rear end of the cylinder of the horizontal rams HR is pressurized through valve 4, all as above described.

When the roof jacks are fully pressurized the trip valve 18 opens to allow the hydraulic fluid carried from the outlet 33 by the pipe 33a to the next subsequent assembly to be pressurized. This being at this time in the position shown in FIGURE 6, the pressure causes the valves 2, 3 and 4 of that assembly to change over to the position of FIGURE 7 and then and only then can the roof supporting jacks of this assembly be released to allow the associated chock to be advanced towards the conveyor all as above described. In this way the assemblies automatically operate in sequence. Furthermore they cannot operate faster than the passage of the machine will allow, because until the roof space has been cleared by the machine the bearer B is held back by the roof and cannot advance from the position of FIGURE 6 to that of FIGURE 5 even though the front end of the cylinder of the ram is connected to pressure, and until it has so advanced the end 14 of member 8 does not engage the abutment A and the valve 1 is not changed over.

It will be clear that since the rear end of the cylinder of the horizontal ram HR is pressurized as soon as the check has been drawn over to the conveyor and the jacks have been pressurized, it is not essential to wait until the machine has completed its traverse before unfixing the conveyor and allowing it to be moved over. If desired, and the construction of the conveyor will allow, this movement can be allowed to take place in stages as the machine moves on, following the movements of the chocks towards the conveyor.

As mentioned above the valve 2 is simply in parallel with the valve 3. Depending on the number of jacks on the chock and the size of the valves, the jacks could be controlled by only a single valve 3 (as assumed for illustration in FIGURES 5, 6 and 7) or by more than two valves in parallel. One of the valves must always control the trip valves 18 and 41, i.e. be arranged like the valve 3.

Another possible modification is that instead of effecting the movement of the member 53 which turns the valves 2, 3 and 4 by hydraulic pressure in both directions, the member 53 may be urged towards the position of FIG- URE 2 (normal position of the valves) by a spring and only be moved in the other direction by hydraulic pressure. In this case the increasing mechanical advantage provided by the mechanism constituted by the cranks 55 and links 54 as the position of FIGURE 2 is approached compensates for the fall in the force of the spring as the latter expands.

It is also advisable that each of the valves 2, 3 and 4 of each assembly should be manually operable to allow for adjustments or movements of the chocks which cannot be obtained automatically.

To this end each of the valves 2, 3 and 4 may be provided with a manual operating means 63, FIGURE 1. When these are to be used to over-ride the automatic operation, the operating means or handle 63 is lifted against the bias of a spring 64. This disengages a dog clutch 6 by which the connection to the valve spindle for automatic ope rationi s normally made and allows the valve to be individually manually operated without altering the setting or positioning of the automatic operating mechanism. One set of dogs is formed of a sleeve 65a carrying the arm 55 the sleeve being loose on the spindle of the plug. The other set of dogs is formed on another sleeve 65b which is keyed to the plug spindle by the usual serrations 656 on the spindle and is longitudinally slidable when pulled by the aid of the knob 63 fixed to the sleeve, against the springs 64. Normally the two sets of dogs are engaged so that motion is conveyed through the arm 55 and the dog clutch to the upper sleeve 65b and so through the serrations 650 to the plug spindle. When the knob 63 is pulled upwards in FIGURE 1 the sets of dogs are disengaged but the sleeve 65b still remains keyed to the spindle and the plug can therefore be rotated by rotating the knob 63.

We claim:

1. A valve assembly for control of equipment of the kind described comprising three plug cocks, means for mechanically actuating the first of the plug cocks between a normal position in which an inlet is connected to an outlet passage, and a pressure release position, a primary trip valve controlling said outlet passage, hydraulically operated means for rotating the second and third of said plug cocks simultaneously between a normal position and a closed position, said first cock when in pressure release position connecting said inlet to said hydraulically operated means in such direction as to rotate said second and third cocks into closed position, and when in its normal position connecting said hydraulically operated means to exhaust, hydraulic means branched ofi an outlet of said second cock for opening said trip valve when said second cock is in its normal position, said second cock in its closed position connecting said hydraulic means to exhaust, said third cock in its normal position connecting 'afurther' inlet to a further outlet and in its closed position closing said further inlet and connecting said further outlet to exhaust.

'2. A valve assembly as set forth in claim 1 also including a non-return valve in the passage controlled by said second plug cock.

3. A valve assembly as set forth in claim 2 also including a secondary trip valve under light closing bias, and hydraulically operated means for opening said secondary trip valve by a supply branched off from the outlet side of said second plug cock.

4. The combination with a valve assembly as set forth in claim 1 of a chock, a conveyor, a hydraulic jack carried by said chock, and horizontal hydraulic ram means on said chock operable towards and away from said conveyor, an abutment on said ram means for actuating the mechanical means for operating said first cock, a supply controlled by said second cock operating said jack, and a 's upplyfor said ram means being controlled by said third bly except the first is connected to the outlet controlled -by the primary trip valve from the first cock of the preceding assembly, and a separate supply is provided to the inlet to the first cock of the first assembly.

8. A series as set forth in claim 7 in which a manually operated master valve is provided for said separate supply. a

9. A combination as set forth in claim 4 also including means for disconnecting said second and third cocks from said hydraulic operating means, and for rotating said second and third cocks manually and independently.

10. A valve assembly as set forth in claim 1 wherein said hydraulically operated means for rotating said second and third plug cocks comprises a hydraulically operated slider.

' 11. A valve assembly as set forth in claim 10 in which the slider is coupled to the cock spindles in a manner such that the mechanical advantage increases as the cocks close.

12. A valve assembly as set forth in claim 11 in which the spindles of the cocks carry crank arms which are actuated through links pivoted between the ends of the crank arms and the slider, the crank arm being substantially parallel to the slider and the links substantially normal thereto when the cocks are closed.

13. A valve assembly as set forth in claim 10 in which the slider is moved hydraulically in a direction to close the second and third cocks, this movement being opposed by a biasing spring.

14. A valve assembly as set forth in claim 10 in which the slider is moved in each direction hydraulically, two

oppositely acting hydraulic cylinders having different effective areas.

15. The combination with a valve assembly as set forth in claim 1 of a chock, a conveyor, a hydraulic jack carried by said check, and horizontal hydraulic ram means on said chock, an abutment on said ram means for actuuating the mechanical means for operating said first cock, a supply controlled by said second cock operating said jack, a supply for said ram means being controlled by said third cock, an adjustable control spring biasing said primary trip valve to its closed position, and a plunger exposed to the pressure in the supply to said jack and acting against the bias of said control spring.

16. The combination with a valve assembly as set forth in claim 1 of a chock, a conveyor, a hydraulic jack carried by said chock, and horizontal hydraulic ram means on said chock, an abutment on said ram means for actuating the mechanical means for operating said first cock, a supply controlled by said second cock operating said jack, a supply for said ram means being controlled by said third cock, said means for mechanically actuating the first of the plug cocks including a pinion coaxial with and secured to the plug of said first plug cock, a rack meshing with said pinion, and means coupled to said rack located in the path of said abutment to be engaged thereby during the last part of the movement of said ram means in the direction of its operation towards said conveyor and displacing said rack to rotate said first plug cock into its normal position.

17. The combination with a valve assembly as set forth in claim 1 of a chock, a conveyor, a hydraulic jack carried by said chock, and horizontal hydraulic ram means on said chock, an abutment on said rams means for actuating the mechanical means for operating said first cock, a supply controlled by said second cock operating said jack, a supply for said ram means being controlled by said third cock, said means for mechanically actuating the first of the plug cocks including a pinion coaxial with and secured to the plug of said first plug cock, a rack meshing with said pinion, and means coupled to said rack located in the path of said abutment to be engaged thereby during the last part of the movement of said ram means in the direction of its operation towards said conveyor and displacing said rack to rotate said first plug cock into its normal position, a casing in which all said plug cocks are housed, and the means coupled to said rack comprising a stern projecting from said casing with its end located in the path of said abutment.

References Cited in the file of this patent UNITED STATES PATENTS 2,977,987 Maynard Apr. 4, 1961 

1. A VALVE ASSEMBLY FOR CONTROL OF EQUIPMENT OF THE KIND DESCRIBED COMPRISING THREE PLUG COCKS, MEANS FOR MECHANICALLY ACTUATING THE FIRST OF THE PLUG COCKS BETWEEN A NORMAL POSITION IN WHICH AN INLET IS CONNECTED TO AN OUTLET PASSAGE, AND A PRESSURE RELEASE POSITION, A PRIMARY TRIP VALVE CONTROLLING SAID OUTLET PASSAGE, HYDRAULICALLY OPERATED MEANS FOR ROTATING THE SECOND AND THIRD OF SAID PLUG COCKS SIMULTANEOUSLY BETWEEN A NORMAL POSITION AND A CLOSED POSITION, SAID FIRST COCK WHEN IN PRESSURE RELEASE POSITION CONNECTING SAID INLET TO SAID HYDRAULICALLY OPERATED MEANS IN SUCH DIRECTION AS TO ROTATE SAID SECOND AND THIRD COCKS INTO CLOSED POSITION, AND WHEN IN ITS NORMAL POSITION CONNECTING SAID HYDRAULICALLY OPERATED MEANS TO EXHAUST, HYDRAULIC MEANS BRANCHED OFF AN OUTLET OF SAID SECOND COCK FOR OPENING SAID TRIP VALVE WHEN SAID SECOND COCK IS IN ITS NORMAL POSITION, SAID SECOND COCK IN ITS CLOSED POSITION CONNECTING SAID HYDRAULIC MEANS TO EXHAUST, SAID THIRD COCK IN ITS NORMAL POSITION CONNECTING A FURTHER INLET TO A FURTHER OUTLET AND IN ITS CLOSED POSITION CLOSING SAID FURTHER INLET AND CONNECTING SAID FURTHER OUTLET TO EXHAUST.
 16. THE COMBINATION WITH A VALVE ASSEMBLY AS SET FORTH IN CLAIM 1 OF A CHOCK, A CONVEYOR, A HYDRAULIC JACK CARRIED BY SAID CHOCK, AND HORIZONTAL HYDRAULIC RAM MEANS ON SAID CHOCK, AN ABUTMENT ON SAID RAM MEANS FOR ACTUATING THE MECHANICAL MEANS FOR OPERATING SAID FIRST COCK, A SUPPLY CONTROLLED BY SAID SECOND COCK OPERATING SAID JACK, A SUPPLY FOR SAID RAM MEANS BEING CONTROLLED BY SAID THIRD COCK, SAID MEANS FOR MECHANICALLY ACTUATING THE FIRST OF THE PLUG COCKS INCLUDING A PINION COAXIAL WITH AND SECURED TO THE PLUG OF SAID FIRST PLUG COCK, A RACK MESHING WITH SAID PINION, AND MEANS COUPLED TO SAID RACK LOCATED IN THE PATH OF SAID ABUTMENT TO BE ENGAGED THEREBY DURING THE LAST PART OF THE MOVEMENT OF SAID RAM MEANS IN THE DIRECTION OF ITS OPERATION TOWARDS SAID CONVEYOR AND DISPLACING SAID RACK TO ROTATE SAID FIRST PLUG COCK INTO ITS NORMAL POSITION. 